Plansifters



June 26, 1962 P. EPPENBERGER PLANSIFTERS 3 Sheets-Sheet 1 Filed Oct. 14, 1959 Zm- ""u f m. A 35d.. n 7: u

iff

June 26, 1962 P. EPFL-:NBERGER 3,040,890

PLANSIFTERS Filed Oct. 14, 1959 3 Sheets-Sheet 2 X Y v BYM.

/1/3 ATTORNEY June 26, 1962 P. EPPENBERGER PLANSIFTERS 3 Sheets-Sheet 3 Filed Oct. 14, 1959 www ism@ ATTO R N EY United States Patent O 3,040,890 PLANSIFTERS Paul Eppenberger, Amriswil, Switzerland, assigner to Gebrueder Bnehler, Uzwil, Switzerland, a Swiss firm Filed Oct. 14, 1959, Ser. No. 846,493 Claims priority, application Switzerland Sept. 16, 1959 18 Claims. (Cl. 209-319) The present invention relates to improvements in plansifters, and more particularly to the construction,` arrangement and sealing of sifter units in plansifter compartments.

This application is a continuation-in-p-art of my application Serial No. 697,572, filed on November 20, 1957, now abandoned.

An important object of the invention is to provide a plansifter whose sifter units, i.e. its collecting bottoms and sifter frames, may be readily and easily inserted, withdrawn and cleaned.

Another important object of the invention is to provide a plansifter embodying a sanitary, simple and reliable sealing arrangement for the sifter frames and collecting bottoms along the surfaces of their abutment with each other and with the supporting structure therefor, whereby the processed goods are prevented from settling in any zone of the plansifter during the sifting operation.

A further object of the invention is to provide a plansifter of the above outlined characteristics whose sifter units are constructed with a view to facilitate their insertion into or their withdrawal from the plansifter compartment.

Still another object of the invention is to provide an improved collecting bottom for use in the plansifter embodying the above outlined advantages.

With the above objects in view, the invention resides essentially in the provision of a plansifter which comprises a housing dening one or more compartments for a number of vertically spaced anged supporting elements which are arranged in aligned pairs in the interior of the housing, and at least one pair of sifter units including a collecting bottom member and a sifter frame member yone of which is supported by the anges of an aligned pair of supporting elements and the other of which is located -above and is slidable with respect to the first mentioned member.

Sealing means may be provided between one of the sifter units and the flanges of respective supporting elements, and additional sealing means may be placed between two adjacent sifter units.

Another feature of the invention resides in the provision of resilient means, e.g. leaf or wire springs, which are adapted to press the sifter units against the flanges of supporting elements to enhance the action of sealing means. The resilient means may be disposed between the sitter units supported by the same pair of supporting elements or between a sifter unit and the flanges of the supporting elements thereabove. Such resilient means may be connected directly to the sifter units or to the flanges of the supporting elements therefor. Alternately, one of the sitter `units may be formed with upwardly projecting extensions which engage with the ilanges of the supporting elements thereabove and compress the yieldable sealing means sufliciently to prevent accumulation of processed goods between the sifter units and/or between a sifter unit and the supporting elements therefor. The advantage of such construction is in that it operates without metallic resilient elements.

An additional feature of the invention resides in the provision of specially arranged battens on selected sifter units which facilitate guiding, sealing and retention of respective units in the plansifter housing without adding to the overall height of the plansifter.

3,640,890 Patented June 26, 1962 The invention will be described in greater detail with reference to the accompanying drawings in which:

FIG. l is vertical section through one compartment of a plansifter embodying the invention, the section being taken on the line I-I of FIG. 2, as seen in the direction of arrows;

FIG. 2 is a vertical section through the plansifter cornpartment taken along the line II-II and at right angles to the section of FIG. l, as seen in the direction of arrows;

FIG. 3 is an enlarged detail sectional view taken on the line III-III of FIG. l, as seen in the direction of arrows;

FIG. 4 is a fragmentary section drawn to a slightly reduced scale and taken along the line IV-IV of FIG. 3, as seen in the direction of arrows;

FIG. 5 illustrates a modification of the construction shown in FIG. 3;

FIG. 6 is a detail view of the modified structure as seen in the direction of arrows from the line VI-VI in FIG. 5;

FIG. 7 is a detail view similar to that of FIG. 6, showing a different mounting of the resilient means;

FIG. 8 illustrates a further modification in a yiew similar to that of FIGS. 3 and 5, showing a sealing arrangement which operates without metallic resilient means;

FIG. 9 is a vertical section taken along the line IX-IX of FIG. 8, as seen in the direction of arrows; and

FIG. 10 is top plan view of a collecting bottom utilized in the modified plansifter of FIGS. 8 and 9.

Referring now in greater detail to the illustrated embodiments, and first to that shown in FIGS. 1 to 4, the plansifter comprises a housing 1 provided with partitions 2 which detine compartments 3. The partitions support horizontally aligned pairs of supporting elements here shown as U-shaped channels 5 each of which is formed with a pair of vertically spaced substantially horizontal anges 6, 7, respectively. rllhe lower anges 7 of each aligned pair of channels 5 slidably support sitter units or frames 9 whilethe upper anges 6 slidably support sifter units in the form of collecting bottoms 10. As is known, the purpose of the members y10 is to collect the fractions passing through the sifter frames thereabove.

A bolting cloth 13 and a wide-mesh wire cloth 14 are stretched across the upper and lower sides, respectively, of each sitter frame 9. Cloth 14 supports means (not shown) for cleaning the cloth 13, `such as pieces of belting, balls or the like. Alternately, the cloth 13 may be cleaned by means of conventional brushes, if desired.

The product fractions to be assorted and classified enter the plansifter through the tubular intake member 30. The fractions passing along and beyond the collecting bottoms 10 are carried away laterally through the ducts 31 in the direction of arrows 48 until deiiected by the members 32 onto the sifter frames 9 and collecting bottoms 10 therebelow. Terminal boxes 33, 34 constitute lateral walls of the plansifter compartment 3. Each terminal box comprises bypass ducts 35, 36 for detouring and discharging the overriding and rejected fractions, respectively. The rejected fractions of the material processed in the plansitter are discharged through tubular outlets 37. The ducts 35, 36 extend the full width of the sifter frames 9, and are separated from each other by U-shaped walls 3S. Certain novel features of the terminal boxes 33, 34 are disclosed `and claimed in my United States Patent No. 2,901,109 for Plansifter Compartment, granted on August 25, 1959.

Each collecting bottom 10 comprises a pair of border battens 21 which are adjacent to its longer sides and which extend from one, e.g. the lower, of its major surfaces. A pair of cross battens 22 is adjacent to the opposing, e.g. upper, major surface and extends along the shorter sides of each member 10. Such arrangement of battens andasse 21, 22 permits full utilization ot the height of the plansitter since the intlow may occur through the entire space between a -bolting cloth 13 and the collecting bottom -10 thereabove. As may be observed in FIG. 3, the vertical spacing between a bolting cloth 13 and'the collecting bottom 10 thereabove corresponds to the helght ot lbattens 21. The same consideration holds true for the outiiow ot treated material.

An important function ot the battens 22 is 1n that their outer surfaces constitute seals against the adjacent terminal boxes 33, 34. As is known, the collecting bottoms 1t) must be mounted at a certain distance trom the sitter trames 9 so that the material passing through the Y cloth 13 and wire screen 14 may ow along the collecting bottoms in the direction 'toward the lateral ducts 31. Thus, the cross battens 22 simultaneously torm seals against the terminal boxes, i.e. there is no increase 1n the height ot a so-constructed plansitter since the space ot a width corresponding to the height of the battens 22 is necessary tor proper operation ot the device.

The outer sides ot the battens 21 are formed with elongated recesses 21r tor the reception ot respective anges 6. Such arrangement prevents a collecting bottom 10 from dropping onto the lower flanges 7 ot the respective supporting elements or channels when the sitter trame 9 therebelow is removed.

As is shown in FIG. 4, each batten 21 carries two lpairs ot retaining pins 25 which support two spaced resilient members in the torm of wire springs 24. These springs bear against and are slidable along the sitter trame 9 therebelow when one ot the sitter units 9, 10 1s moved with respect to the other unit, i.e. when either the collecting bottom '10 or the sitter ytrame 9 therebelow is inserted into or removed from the plansitter compartment 3. In addition, these springs cause the members 10, 9 to bear against the upper and lower ilanges 6, 7, respectively, of an aligned pair ot supporting elements or channels 5. Thus, the mounting ot resilient means 24 is such that they urge a collecting bottom in a direction away ytrom the sitter trame 9 therebelow.

Sealing strips of suitable yieldable elastic material, indicated by reference numerals 26., are provided between the sitter trames. 9 and the respective anges 7. These strips extend into and are retained in elongated recesses A9a Vformed in the undersides of the sitter trames 9. Re-

cesses 9a are parallel with the lower lianges 7 ot supporting elements 5. The sealing action ot the strips 26 is enhanced by the resilient means 24 which constantly urge the sitter frames 9 toward their respective anges 7.

In the absence of a collecting bottom (see, tor example, the top of FIG. 3), special battens 27 are provided tor bracing the uppermost sitter trame 9, i.e. `for urgingthe uppermost sitter trame against the anges 7 forming part ot the uppermost pair ot supporting elements or channels 5. The battens 27 are slidable beneath the uppermost pair of flanges 6 and carry resilient means preferably identical with the springs 24 which bear against the upper side ot the adjacent sitter trame 9.

FIG. 5 illustrates a modiiication ot the system shown in FIGS. l to 4 whose purpose is to prevent entry ot product fractions between the battens 21 ot the collecting bottoms land the sitter trames 9 therebelow. As mentioned hereinbetore, the resilient means 24 urge the battens 21 in a direction upwardly and away trom the sitter frames 9 therebelow; thus, a slot X (shown greatly exaggerated in FIG. 4) develops between the sitter unit 9 and the battens 21. This slot is rapidly tilled with comminuted goods, which is highly undesirable. To prevent the formation ot such slots, a second sealing strip 40 is provided between each batten 21 and the sitter trarne 9 therebelow. The modied construction ot FIG. 5 utilizes L-shaped supporting elements 41 whose horizontal flanges l42 abut against the undersides of the sitter frames 9 with the `sealing strips 26 therebetween. Adjacent to the sealing strip 40, each batten 21 is formed with a downwardly projecting elongated rib 2lb which extends into a recess 9b -tormed in the sitter trame 9 therebelow. The depth ot each recess 9b preferably exceeds the height of the respective rib 2lb, which enables the resilient eans 43 to compress the yieldable sealing strip 40 when the collecting bottom is inserted into the plansitter compartment. Each of resilient means 43 preferably assumes the shape ot a semielliptical leaf spring one end of which is tree to slide along the collecting bottom when the spring is compressed by the flange 42 thereabove. Such construction of the leat springs facilitates the insertion ot collecting bottoms into the plansifter compartment. Resilient means 43 are mounted on the upper sidesot the battens 21 forming part ot collecting bottoms 10, and bear against the undersides of the flanges 42 thereabove. Thus, instead ot urging a collecting bottom f1() away from the sitter trame 9 therebelow, the springs 43 urge the collecting bottoms 1t? in downward direction to enhence the sealing action ot strips 26 and 4t). Such construction brings about the important advantage that the sealing strips prevent escape of processed goods laterally between the undersides of battens 21-and the upper sides ot the sitter trames 9 into contact with the supporting elements 41, i.e. the sealing means are closer to the path ot the conveyed material. The sealing strips 26, 40 may consist ot felt, plush, or any other suitable resilientlyyieldable material.

The uppermost sitter frame 9 shown in FIG. 5 cooperates with a retaining and spacing trame member `consisting of battens 21a, 22a, the former ot which also carries ia `lea-t' spring 43 bearing against the flange 42 ot the supporting element 41 thereabove. The retaining and spacing trame member consisting ot battens 21a, 22a replaces a collecting bottom 16 and permits unimpeded descent of processed goods directly onto the sitter trame 9 therebelow. In addition, the retaining frame member holds the uppermost sitter trame in requisite position during the sitting operation, i.e. this special frame member also perfor-ms the function of the battens 27 shown in FIG. 3.

As is shown in FIG. 7, the resilient means 43 may be attached to the undersides ot the anges 42 to bear against the upper sides of the battens 21.

Each collecting bottom 10 may be formed with at least one substantially convex protuberance 44 which constitutes a handgrip means and facilitates the withdrawal ot the collecting bottom trom the plansifter compartment. It can be observed in FIG. 6 that the space between a cross batten 22 and the sitter trame 9 `thereabove is rather narrow, i.e. it is insuiiicient to permit insertion of the fingers which could grip the batten 22 to withdraw the collecting bottom 10 from the plansi-fter compartment. By providing the aforementioned bulges or protuberances 44, the operator can insert his iingers into the concave recesses or cavities formed at the undersides ot the collecting bottoms to withdraw the latter against the force ot the resilient means 43. Upon withdrawal ot the collecting bottom, the operator has no ditculty in removing the sitter trame 9 which is then -treely slidable along the flanges 42 ot the corresponding supporting elements 41. Alternately, the protuberance 44 may be replaced by another handgrip means, for example, by a pin ora handle located below the batten 22. The provision of handgrip means in the form ot protuberances has the advantage that the protuberances do not restrict the inlet openings to the sieves therebelow,

FIGS. y8 to l0 illustrate a modification ot the assembly shown in FIGS. 5 and 6. The battens 21, 21a comprise upwardly projecting extensions 45 which replace the resilient means 143. Each extension is formed with two inclined surfaces `46 which facilitate the insertion ot the collecting bottom, and each extension is preferably coated with a yieldable sealing material 47, e.g. a layer ot plush, telt or the like. The extensions 45 bear against the undersides of the respective flanges 42 and thus compress the sealing strips 26 and 4b by urging the latter against the upper sides of the sifter frames 9 and against the upper sides of the anges 42, respectively. Thus, the arrangement of FIGS. 8 and 9 operates without metallic springs as it merely utilizes the resiliency of yieldable sealing strips or layers 26, 40 and 47 for holding the sifter frames 9 and collecting, bottoms 10 in required operative position. FIG. l illustrates that an extension 45 is provided at each of the four corners of a rectangular collecting bottom 10.

A simplified version of the construction shown in FIGS. 8 and 9 utilizes only the sealing strips d0, i.e. the sealing strips 26 and 47 may be omitted, as long as the height of projections or extensions 45 is selected in such a way that these extensions cause suiiicient compression of sealing strips 40 when the collecting bottoms lo are inserted into the plansifter housing.

The operation of the assemblies shown in FIGS. 6 and 8-9 is as follows:

The sifter frames 9 are held against movements with respect to the adjacent iianges 42 by the collecting bottoms 10 and by the spacer frame members 21a, 22o thereabove. rPhe sealing strips 4d prevent entry of conveyed material into the spaces between the sifter frames 9 and the battens 21 or 21a thereabove; thus the goods travelling laterally along the screens 13 of sifter frames 9 can find no crevices or slots and cannot remain in the plansifter.

The goods passing along the upper sides of collecting bottoms 10 advance into the ducts 31 (see the arrows 4S). The goods which cannot pass the bolting cloths I3 are discharged in the direction of arrows 49 and descend in the ducts 3S or 36 onto selected sifter frames therebelow (see FIG. l). As mentioned hereinbefore, the frame members consisting of battens 21a, 22a permit the descent of goods from the inlet duct 343 or from a higher sifter frame directly onto the next-lower sifter frame. The handgrip means 44 shown in FIGS. 5 and 6` need not be provided on the spacer frame members because the transverse battens 22a are readily accessible and may be grasped by an operators hand to permit convenient Withdrawal of such spacer frame members from the plansifter compartment. Once the collecting bottoms it] or the spacer frame members are removed, the retaining action upon the sifter frames is terminated and the latter then offer no resistance during their withdrawal from the plansifter.

I Wish it Ito be understood that I intend to include as within the scope of my present invention all such modiications as may be necessary -to adapt the plansifter to varying conditions and uses and which fall within the terms or spirit of the appended claims.

I claim:

l. In a plansifter, in combination: a housing; vertically spaced pairs of parallel supporting elements in said housing, each supporting element having at least one flange; a sifter frame member and a collecting bottom member in said housing, one of said members being slidably supported by the flanges of one pair of said supporting elements and the other `member being located above and slidable on said one member.

2. The structure as set forth in claim l, wherein said one member has an underside and further comprising sealing means between said underside and the flanges of the respective supporting elements.

3. 'I'he structure as set forth in claim l, further comprising sealing means between said sifter frame member and said collecting bottom member.

4. 'Dhe structure as set forth in claim 1, further comprising resilient means located between said other member and the flanges of supporting elements thereabove for urging said other member in a direction toward said one member.

5. In a plansifter, in combination: a housing; vertically spaced pairs of parallel horizontal supporting channels in said housing, each channel having :a first flange and a second iiange vertically spaced from said -first ange, a sifter frame member slidably supported by the first flanges of one pair of said channels; and a collecting bottom member having a first and a second pair of sides and a first and a second major surface, and comprising a tirst pair of battens each extending along one of the vfirst pair of said sides at one of said major surfaces, and a second pair of battens each extending along one of the second pair of said sides at the other of said major surfaces in sliding contact with the second flanges of said one pair of channels.

6. In a plansifter, in combination: a housing; vertically spaced pairs of parallel horizontal supporting channels in said housing, each channel having an upper flange and a lower iiange; a sifter frame member and a collecting bottom member slidably supported by a pair of said supporting channels; and spring elements operating between said members for urging one member against the upper anges and the other member against the lower flanges of the respective pair of said channels.

7. The structure as set forth in claim 6, wherein the bottom member has a first and a second pair of sides and further comprising a first pair of battens each thereof extending along one of the first pair of said sides above the collecting bottom member, and a second pair of battens each thereof extending along one of the second pair of said sides below the collecting bottom member.

8. The structure as set forth in claim 6, further comprising a pair of sealing strips fixed to the sifter frame member and abuttingT against the lianges against which the sifter frame member is urged by said spring elements.

9. The structure as set forth in claim 6, wherein the sifter frame member is disposed below the collecting bottom member and is urged by said spring elements against the lower flanges of the respective pair of said channels.

l0. The structure as set forth in claim `6, further comprising a pair of battens insertable into said housing as a replacement for said collecting bottom member, each batten being disposed above the sifter frame member and slidable along an upper flange of the respective pair of Vsaid channels, and spring elements operating between said battens and the `sifter frame member for urging the latter against the lower flanges and for urging the battens against the upper flanges of the respective pair of said channels.

1l. As a novel article of manufacture for use in a plansifter, a collecting bottom member having a first and a second pair of sides and two major surfaces; a first pair of battens each extending along one of the first pair of said sides adjacent to one of said surfaces; and a second pair of battens each extending along one of the second pair of said sides adjacent to the other of said surfaces.

l2. In a plansifter, in combination: a housing; vertically spaced pairs of parallel supporting elements in said housing, each supporting element having a substantially horizontal flange; a sifter frame member and a` collecting bottom member in said housing, one of said members being slidably supported by the flanges of one pair of said supporting elements and the other member being located above and slidable with respect to said one member; sealing strips of resiliently yieldable material between said members, each strip extending in parallelism with one of said flanges; `and means located between said other member and the lianges of the pair of supporting elements thereabove for urging said other member in a direction toward said one member and for compressing said sealing strips.

13. The structure as set forth in claim 12, wherein said sifter frame member is located below said collecting bottom member and has an underside formed. with a pair of spaced parallel recesses adjacent to the respective `frame member and comprises a pair of downwardly eX- tending parallel battens, each batten having an underside and said sealing strips being fixed to the undersides of said battens.

15. The structure as set forth in claim 14, wherein each of said battens comprises a downwardly extending rib adjacent to the respective sealing strip, and said sitter frame member is formed with recesses for the reception of said ribs.

16. In a plansifter, in combination: a housing; vertically spaced pairs of parallel horizontal supporting elements in said housing, each supporting element having a substantially horizontal lflange; a sitter frame member in said housing resting on the lllanges of one pair of said supporting elements; a collecting bottom member above said sifter frame member, said collecting bottom member having Ia pair of parallel battens extending in paral- Cil lelism with the flanges of said supporting elements and each batten comprising at least one upwardly projecting extension engaging with the flange of the supporting element thereabove for urging ythe sifter ramemember against the flanges of the supporting elements therebelo-w; and `a sealing strip of yieldable material inserted between each batten and the sitter frame member.

17. The structure as set forth in claim 16, wherein each of said extensions is formed with at least one inclined surface for facilitating the insertion of said collecting bottom member into the plansifter housing.

18. The structure as set forth in claim 16, wherein said collecting bottom member is of rectangular contour and an extension is provided at each of its four corners.

References Cited in the tile of this patent UNITED STATES PATENTS 2,191,923 Ceckal Feb. 27, 1940 20 2,648,441 Soldan Aug. 11,1953

FOREIGN PATENTS 567,632 Canada Dec. 16, 1958 724,985 Great Britain Feb. 23, 1955 

